Volume 64, Issue 9-10

Z. Naturforsch. 64 c, 611 - 614 (2009); received March 1/30, 2009 The hydrodistilled essential oil content of Origanum majorana L. (Lamiaceae) ranged from 2.5 - 3% with the maximal value (3%) in spring. Analysis of the oil by GC/MS resulted in the identifi cation of 15, 15, 11, and 14 components in the oils prepared in spring, summer, autumn, and winter, respectively. The composition of the essential oils differed quantitatively and qualitatively according to the time of collection. Thymol (38.4%) and cis-sabinene hydrate (25.3%) were the major components in spring plants. Terpinen-4-ol (37.4%, 20.5%, 16.3%) was a major component in the summer, autumn and winter oils, respectively. cis- Sabinene hydrate (54.4%) was major in winter plants while terpinolene (43.1%) was the main component in autumn plants. Other components detected in lower amounts in all oil samples were sabinene and p-cymene (up to 7.4% and 13.9% in autumn), and α-terpinene (up to 13.3% in summer)

3-[(1-Methylpyrrol-2-yl)methyl]-4-substituted 4,5-dihydro-1H-1,2,4-triazol-5-ones were obtained by the cyclization reaction of 1-[(1-methylpyrrol-2-yl)acetyl]-4-substituted semicarbazides in alkaline medium. The effects of the synthesized compounds of the central nervous system of mice were studied

The lipid-lowering effects of two novel antihyperlipidemic agents, BMI2C [N-(4-benzoylphenyl)- 5-methoxy-1H-indole-2-carboxamide] and DDMI2C [N-(9,10-dihydro-9,10-dioxoanthracen- 2-yl)-5-methoxy-1H-indole-2-carboxamide], were studied using hyperlipidemic rats as an experimental model; hyperlipidemia was developed by intraperitoneal injection of Triton WR-1339 (200 mg/kg body weight). At a dose of 15 mg/kg body weight, BMI2C and DDMI2C signifi cantly reduced elevated plasma triglyceride levels after 7 and 24 h. Furthermore, BMI2C and DDMI2C significantly reduced elevated plasma total cholesterol levels after 24 h. Interestingly, high-density lipoprotein-cholesterol levels were significantly increased in all treated groups. These findings indicate that the two studied novel compounds have a promising potential in the treatment of hyperlipidemia and atherosclerosis

Oxidative stress is believed to be a major contributing factor in the development of late complications of diabetes. Many in vitro and in vivo studies have demonstrated that several parameters of red blood cell function and integrity are negatively affected by increased oxidative stress. Plant polyphenols are reported to exert many biological effects due to their antioxidant property. The present study was undertaken to evaluate the antioxidant effect of myricetin on markers of oxidative stress in erythrocytes from type 2 diabetic patients. The study was carried out on blood samples obtained from 23 type 2 diabetic patients and 23 age-matched control subjects. Erythrocytes were subjected to in vitro oxidative stress by incubating with 10 -5 M tert-butyl hydroperoxide (t-BHP). Erythrocyte membrane lipid peroxidation and protein oxidation were measured in terms of malondialdehyde (MDA) and protein carbonyl group levels. The results showed an elevated MDA and protein carbonyl content in diabetic erythrocytes which were further increased after incubation with t-BHP. Myricetin at micromolar concentration significantly (p < 0.01) protected an t-BHP-induced increase in levels of oxidative stress parameters of diabetic erythrocytes

A general, facile method to synthesize the N'-alkyl and N',N'-dialkyl derivatives of Lglutamine 1a-d from L-glutamic acid as a starting substrate is presented. The obtained compounds are shown to inhibit three different glutamine-utilizing enzymes, namely: glutaminase, γ-glutamyl transpeptidase, and glucosamine-6-phosphate synthase, with inhibitory constants within the millimolar range

A detailed chemical study of the aerial parts of Tamarix nilotica (Tamaricaceae) from Saudi Arabia led to the isolation of a new pentacyclic triterpenoid, 3-O-trans-caffeoylisomyricadiol, in addition to nine known compounds. The structures of all isolated compounds were unambiguously elucidated by 1D, 2D NMR, and mass spectrometry. In the radical scavenging (DPPH) assay, 3-O-trans-caffeoylisomyricadiol exhibited potent antioxidant activity with an IC 50 value of 3.56 μM, while that for quercetin (standard antioxidant) was 5.72 μM

In continuation of our interest in phytochemical screening of the Egyptian flora for potential drugs, the reinvestigation of the methanolic extract of the roots of Solanum diphyllum, which grows naturally in the south of Egypt and is recorded as new to the Egyptian flora, afforded an interesting, highly cytotoxic compound, named 3-O-(β-D-glucopyranosyl) etioline [(25S)-22,26-epimino-3β-(β-D-glucopyranosyloxy) cholesta-5,22(N)-dien-16α-ol]. The chemical structure of this compound was determined by comprehensive NMR studies, including DEPT, COSY, HMQC, and MS. The compound exhibited high cytotoxic effects against the cervical cancer cell line, Hela cells, with an IC 50 value of 150 μg/mL

Two new diterpenes were isolated from stems and leaves of Xylopia langsdorffi ana, entatisane- 7α,16α-diol (xylodiol) and ent-7α-acetoxytrachyloban-18-oic acid (trachylobane), along with the known 8(17),12E,14-labdatrien-18-oic acid (labdane). We investigated their antitumour effects on HL60, U937 and K562 human leukemia cell lines. We found that xylodiol was the most potent diterpene in inhibiting cell proliferation of HL60, U937 and K562 cells, with mean IC 50 values of 90, 80 and 50 μM, respectively. Based on the nitroblue tetrazolium (NBT) reduction assay, all the diterpenes were found to induce terminal differentiation in HL60 and K562 cells, with xylodiol being the most effective. NBT reduction was increased by almost 120% after 12 h exposure of HL60 cells to xylodiol at a concentration lower than the IC 50 (50 μM). Thus, xylodiol inhibited human leukemia cell growth in vitro partly by inducing cell differentiation, and merits further studies to examine its mechanism of action as a potential antitumoural agent

Phenolic compounds are found in seaweed species together with other substances presenting antioxidant activity. The objective of this work was to evaluate the antioxidant activity of the free phenolic acids (FPA) fraction from the seaweed Halimeda monile, and its activity to protect the expression of hepatic enzymes in rats, under experimental CCl4 injury. The antioxidant activity was measured by the DPPH method. The FPA fraction (80 mg/kg, p.o.) was administered during 20 consecutive days to rats. The peroxidation was performed by thiobarbituric acid reactive substances (TBARS). The SOD and CAT enzymatic expressions were measured by RT/PCR. The histology technique was used to evaluate liver injuries. The expression of both, CAT and SOD genes, was more preserved by FPA. Only partial injury could be observed by histology in the liver of rats receiving FPA as compared with the control group; and CCl 4 administration induced 60% more peroxidation as compared with the rats receiving FPA. These data suggest that FPA could modulate the antioxidant enzymes and oxidative status in the liver through protection against adverse effects induced by chemical agents

The activities of perlatolic acid (1), atranorin (2), and lecanoric acid (3) and their derivatives, such as orsellinates and β-methyl orsellinates obtained by alcoholysis, were assessed for stimulation of the release of hydrogen peroxide and nitric oxide in cultures of peritoneal macrophage cells from mice. The hydrogen peroxide production was estimated by oxidation of phenol red, while the Griess reagent was used to determine the nitric oxide production. 1 and 4-methoxy-ethyl orsellinate (XVII) were the compounds that induced the greatest release of H 2 O 2 , whereas n-pentyl orsellinate (IV), iso-propyl orsellinate (V), sec-butyl orsellinate (VI), and XVII induced a small release of NO. These results indicate that lichen products and their derivatives have potential immune-modulating activities

An analysis of the shape of photosynthetic light curves is presented and the existence of the initial non-linear part is shown as a consequence of the operation of the non-cooperative (Kok’s) mechanism of oxygen evolution or the effect of dark respiration. The effect of nonlinearity on the quantum efficiency (yield) and quantum requirement is reconsidered. The essential conclusions are: 1) The non-linearity of the light curves cannot be compensated using suspensions of algae or chloroplasts with high (>1.0) optical density or absorbance. 2) The values of the maxima of the quantum efficiency curves or the values of the minima of the quantum requirement curves cannot be used for estimation of the exact value of the maximum quantum efficiency and the minimum quantum requirement. The estimation of the maximum quantum efficiency or the minimum quantum requirement should be performed only after extrapolation of the linear part at higher light intensities of the quantum requirement curves to “0” light intensity

The non-linearity of photosynthetic light curves and the real reasons leading to the appearance of the “red drop of quantum efficiency” and “enhancement” (Emerson’s second) effects are presented. On the contrary to the generally accepted interpretation that these effects are induced from the participation of the two different photochemical systems, it is shown that they are simply a direct consequence of the initial non-linearity of the photosynthetic light curves

A hairy roots culture of Pueraria candollei was established using Agrobacterium rhizogenes ATCC15834 and grown in half-strength Murashige and Skoog (MS) medium. The highest production of total isoflavonoids was found to be (36.48 ± 4.09) mg/g dry wt [(3.39 ± 0.20) mg/g dry wt puerarin, (29.91 ± 3.74) mg/g dry wt daidzin, (1.65 ± 0.09) mg/g dry wt genistin, (0.76 ± 0.03) mg/g dry wt daidzein, and (0.76 ± 0.03) mg/g dry wt genistein, respectively]. The total isoflavonoid content in hairy roots of P. candollei was 5.18-fold higher than that of the native tuber. Effects of sucrose content and medium type on growth and isoflavonoid production were investigated. 5% (w/v) Sucrose was an optimum content for the growth and isoflavonoid accumulation in P. candollei hairy roots. Half-strength MS medium had the highest effect for biomass production whereas woody plant medium had mostly stimulated isoflavonoid content in hairy roots

A hairy roots culture of Stephania suberosa was established using Agrobacterium rhizogenes ATCC15834. The production of dicentrine was found to be (8.92 ± 0.07) mg/g dry wt on day 35 of culture. Effects of sucrose content, tyrosine, and medium strength on growth and dicentrine production of S. suberosa were investigated. 6% (w/v) sucrose was an optimum content for the growth and dicentrine accumulation in S. suberosa hairy roots. The utilization of a precursor from tyrosine feeding enhanced the dicentrine production. The medium with 1.0 mM of tyrosine had the highest effect on dicentrine accumulation in hairy roots at day 40 of culture [(14.73 ± 0.47) mg/g dry wt]. In addition, ¼ Murashige and Skoog medium was suitable for biomass and dicentrine production in hairy roots. This culture system has a potential to produce dicentrine from hairy roots of S. suberosa

In order to evaluate the hypothesis that nitrate uptake is under positive control by sugars, a simple noninvasive model was used to measure the effects of nine modulating sugars on the net nitrate uptake in rice under constant low nitrate concentration. The results showed that the fastest and greatest acceleration in nitrate uptake were observed after sucrose was added, and this change reached a peak 1.5 h after treatment. In addition, we found that 1 mM sucrose could affect the nitrate uptake in rice roots for 8.5 h. The three most positive effective sugars and one negative effective sugar were selected for further analyzing their effect on the expression of nitrate transporter gene OsNrt2.1. The result of RT-PCR showed that the expression of OsNrt2.1 was upregulated by sucrose, glucose and galactose. Among the three positive effective sugars tested, sucrose was found to have significant and continuous enhanced stimulation on OsNrt2.1 gene expression within 4 h, which indicated that sucrose could be as a specific signal to regulate the net nitrate uptake

Drought stress significantly enhanced the capacity of the alternative respiratory pathway and induced AOX1a and AOX1b transcripts in rice seedling leaves. The drought-stressed seedlings pretreated with the inhibitor of the alternative respiratory pathway, 1 mM salicylhydroxamic acid, had a lower level of relative water content than the seedlings either subjected to drought or salicylhydroxamic acid treatment alone. This observation suggests that the alternative respiratory pathway could play a role in the tolerance of rice seedlings to drought stress. Pretreatment with exogenous hydrogen peroxide, salicylic acid, and abscisic acid alone mitigated the water loss of rice leaves exposed to drought stress. Exogenous application of hydrogen peroxide and salicylic acid increased the capacity of the alternative respiratory pathway and induced AOX1a and AOX1b transcripts, while exogenous abscisic acid failed to induce any expression of AOX1 genes. These observations suggest that rice AOX1a and AOX1b genes may be responsive especially to drought stress but not be induced by all of the stress signals related to drought

Polymerase chain reaction (PCR) amplification with primers specific to the rDNA region successfully amplified the 1160-bp DNA fragment from a Huanglongbing (HLB)-infected sweet orange sample with mottling symptoms leaves, but not from healthy sweet orange plants. The PCR product of 1160-bp was used as probe labeled with biotin for detection of the HLB pathogen in the nucleic acid spot hybridization (NASH) test. It was found that the HLB pathogen could be detected up to 1:100 dilution in HLB-infected tissue. Total DNA extracted from HLB-infected tissue was diluted 2-fold as 900 ng in TE buffer and spotted on a nitrocellulose membrane. Strong signals were observed up to 225 ng of DNA dilution, whereas a moderate signal was recorded at 112 ng. No hybridization signal was observed in the healthy samples, while strong signals were observed in the positive control

Pseudevernia furfuracea (L.) Zopf lichen specimens were collected every 5 km starting from around an iron-steel factory located in the central area of Karabük province, up to Yenice Forest. Zn, Cu, Mn, Fe, Pb, Ni, Cd, Cr contents were analyzed in the samples collected from polluted and unpolluted areas. A Pseudevernia furfuracea (L.) Zopf sample from Yenice Forest was used as a control. The reason for this choise was the abundance of species diversity, and therefore sample collection might cause a very low impact on natural population density. The forest is among the 100 forested areas that must be urgently taken under protection according to WWF (World Wildlife Fund) researches. Results of the current study manifested significant variations among the contents of these elements between stations. As expected, the pollution sources, such as iron-steel factory, roads and railroads, industry, heavy traffic, and waste treatment plants, have major impact on the heavy metal accumulation in P. furfuracea (L.) Zopf, and, in accordance to their location, samples 8 and 10 displayed high element accumulation. Surprisingly, although Yenice Forest is under protection, results of our study showed that the region is becoming polluted by the infl uence of many pollution sources in the area. The present study also confirms the efficient metal accumulation capacity of lichens

The bacterium Streptomyces albus has so far never been investigated for tyrosinase activity. The studies presented in this communication show that this bacterium may be a future source for larger production of tyrosinase. The enzyme was purified starting with 5,600 ml of culture filtrate. The crude enzyme was first purified by centrifugation, followed by ammonium sulfate precipitation and ultrafiltration. Then, melanin was removed applying a Servacell DEAE 52 resin, using the batch technique. Thereafter, the crude enzyme was loaded on a SEC Sephacryl S-100 column and, after ultrafiltration, 1.17 mg of purified tyrosinase were obtained. The molecular mass of the purified enzyme was determined by MALDI mass spectrometry to be 30,096 Da which corresponds to the obtained results from SDS-PAGE. Using the diphenol L-DOPA and the monophenol L-tyrosine as substrates, the kinetic parameters for both substrates, K m = 7.8 mM and 0.5 mM and k cat /K m = 157 mM -1 s -1 and 23 mM -1 s -1 , respectively, were determined. Maximal activities of the purified enzyme were recorded at pH 7.0. Long-term experiments with Streptomyces albus tyrosinase revealed that storage of the lyophilized enzyme sample at temperatures below zero turned out to be the best. For tyrosinase in buffer containing 20% glycerol, no loss of activity was observed at 4°C and - 60°C

3,7-Dimethylpentadecan-2-ol and 3-methylpentadecan-2-ol were identified in female whole body extracts from the two pine sawfly species Gilpinia frutetorum and Gilpinia socia. This is the first observation of 3-methylpentadecan-2-ol in extracts of a female pine sawfly species. Synthetic and highly pure stereoisomers of 3,7-dimethylpentadecan-2-ol and 3-methylpentadecan-2-ol were used to verify that the (2S,3R,7R)-isomer of 3,7-dimethylpentadecan- 2-ol and (2S,3R)-3-methylpentadecan-2-ol were present in the extracts. The four stereoisomers of 3-methylpentadecan-2-ol and their biologically active esters were produced via chemoenzymatic methods and the synthesis is described in detail. Male G. socia antennae responded strongly in EAG recordings to the (2S,3R)-isomer of the acetate and propionate of 3-methylpentadecan-2-ol. Male antennae of both G. frutetorum and G. socia also responded to the (2S,3R,7R)- and (2S,3R,7S)-acetates of 3,7-dimethylpentadecan-2-ol

The aim of the research was to determine the influence of strong hypergravity on the Paramecium bursaria-Chlorella sp. symbiotic association, which is considered to be a model example of symbiosis between a heterotroph and an autotroph. The paramecia cells were exposed to 1073 × g, 4293 × g, and 9658 × g hypergravity for 15 min. Then they were incubated for 21 d on a standard lettuce medium. The experiments were conducted in parallel under constant white light and in the dark. The changes in the number of paramecia cells during incubation were determined. Measurements of the number of Chlorella sp. endosymbionts inside host cells were also made. The results showed that a 15-min exposure to hypergravity attenuates the subsequent growth of Paramecium bursaria in the dark, but it may stimulate the growth of paramecia under constant light. Moreover, it causes an increase in the number of algae inside the paramecia cells. Presumably, the influence of hypergravity on the studied symbiotic complex is connected with its effect on the endosymbiotic Chlorella sp. cells. This subject requires further research, focused on the influence of hypergravity on the physiology and growth of the Chlorella sp. endosymbionts living inside the Paramecium bursaria cells

Dynein-ATPase is the intracellular motor for sperm motility. In the present work we assayed the dynein-ATPase activity in an axoneme-containing fraction of human sperm, free of plasma membranes, in normozoospermic and asthenozoospermic donors. Axonemecontaining fractions were isolated from semen samples obtained from healthy donors with either normozoospermia or asthenozoospermia, as indicated by a sperm motility lower than 50% (WHO grade a + b). The dynein-ATPase activity was assayed and partially characterized. The dynein-ATPase activity in the axoneme-containing fractions was identified as Mg 2+ -dependent ATPase activity inhibited by 10 μM vanadate. This inhibition was not seen when the assay was done in the presence of 1 mM norepinephrine. The dynein-ATPase activity is Mg 2+ -dependent, Li + -sensitive, and insensitive to 2 mM ouabain, 1 μM oligomycin, and 1 μM thapsigargin. The dynein-ATPase activity was significantly lower (p < 0.001) for asthenozoospermic donors as compared to normozoospermic donors. This is a straightforward dynein-ATPase assay that can be used to obtain data of functional interest in clinical or experimental settings

Enolase detected on the cell surface may be a receptor for certain ligands, especially for plasminogen. It is important for the pathogen invasiveness and in the development of a tumour. Therefore, we sought to preliminarily determine the enolase location and catalytic activity in the subfractions of MCF-7 cells. The latter was done on intact cells and in subfractions of MCF-7 cells. We identified enolase by immunoblotting. The binding of human plasminogen to enolase was performed by immunoblotting using monoclonal antibodies against plasminogen. The intact MCF-7 cells demonstrated activity of enolase. Enolase in postnuclear and perinuclear fractions is catalyticly active too. We identified the enolase protein in immunoblots of these fractions, except for the nuclear subfraction. These results provide evidence that enolase is present on the intact surface of MCF-7 cells and in post- and perinuclear fractions. The surface protein maintained catalytic activity, which suggests that its location in the plasma membrane didn’t change the active centre of the enzyme

3-Hydroxyindole was isolated from the EtOH extract of fruits of Aristotelia chilensis during analyses by HPLC/MS and GC/MS and identifi ed by its mass fragmentation pattern and spectrophotometric data. Additionally, this extract showed an interesting antioxidant activity in DPPH, crocin and TBARS assays. The presence of this type of compound in this fruit species permits us to explain its strong antioxidant activity and its important part in the biosynthetic pathway of phenolic and alkaloid compounds in this plant. Therefore this compound could be useful for the development of future nutraceutical and antioxidant protective agents